It is well known to cast straps and other formations on the lugs of battery plates, for example to connect together each of the plates in a group. In almost all cases this is done by filling a mould cavity with lead and dipping the lugs into that cavity. In order for an acceptable connection to be made between the lead and the lug, the temperature of the lead at the interface needs to be above the freezing point of lead. In general this requires the lead block to be heated by a heat source, such as a gas flame, until the lugs are dipped into a cavity and then cooling has to occur so that the lead solidifies quickly. Most such heating arrangements are inefficient and expensive. Attempts have been made to dip the mould block into a pot of molten lead in order to achieve the desired result, but this precludes the use of ejector means for removing the cast on straps from the mould, because the lead would clog up and such moveable parts.
The more normal method of filling the mould cavities is to flow lead in channels to the side of the cavities and allow it to spill over weirs. This can require very great control of lead flow, if one is to ensure that the cavities are filled but the mould as a whole is not over filled.